The proposed research project will determine if chronic exposure to subanesthetic and anesthetic concentrations of the inhalational anesthetics, halothane, nitrous oxide, methoxyflurane, enflurane and isoflurane, adversely effect the reproductive processes. The necessity for performing such studies has been suggested by recent surveys which have shown an increased incidence of fetal wastage and congenital abnormalities in operating room personnel. We propose to examine the effects of inhalational anesthetics on: 1) fertility; 2) gonadal histology; 3) mating behavior; 4) in utero fetal viability; 5) fetal size; 6) postnatal survival of offspring, and 7) fertility of offspring. Male and female Swiss/1CR mice will be exposed to the test drug for nine weeks prior to mating, during mating and throughout gestation. One day prior to term, cesarean sections will be performed on two-thirds of the pregnant females and the uterus and its contents examined. The remaining one-third will be allowed to deliver so that their offspring may be observed up to the time of weaning. Randomly selected offspring will be maintained for subsequent examination of reproductive performance. From these experiments we should be able to determine if inhalational anesethetic agents have a significant effect upon reproductive processes in Swiss/1CR mice. Ultimately, these results may be of value in assessing the hazard of subanesthetic exposure to operating room personnel and of anesthetic exposure to patients.